On Sun, 13 Feb 2011, Petr Baudis wrote: > I think it would be great if you could add some text like this plus some > rationale (AIUI, this is geared mainly at new Atoms and other x86_64 > embedded platforms) to the document. > > (BTW, it is not really convincing to me that such a niche is worth all > the trouble this is going to bring.)
It seems to me there's a much more general utility for this. After all, the normal practice on 64-bit Power Architecture GNU/Linux systems, say, is for most programs to be 32-bit and only a few that have a use for a large address space to be 64-bit. For most programs, large pointers and size_t are just a waste of memory (and so of cache) - but the extra registers are significantly beneficial (as are such things as being able to assume SSE to be supported). (Large files, 64-bit time_t, etc., however, are of wider use than large address space, but as I noted in <http://gcc.gnu.org/ml/gcc/2010-12/msg00509.html> it would be a fairly substantial project to address all such issues of inappropriate arbitrary limits in C APIs.) -- Joseph S. Myers jos...@codesourcery.com
